An Arc-Fault Circuit Interrupter (AFCI) is a device that is designed to mitigate the effects of arcing faults by functioning to de-energize the circuit when an arc fault is detected. Specifically, AFCI devices detect the presence of parallel arcing and series arcing in AC power systems. When arcing is detected, the AFCI device opens the electrical branch protected by the device. Arcing faults typically occur in damaged or deteriorated wires and cords. Some causes of damaged and deteriorated wiring include puncturing of wire insulation, natural aging and wire exposure to heat vents or harsh environmental conditions.
Prior art devices for testing AFCI devices typically employ a series arcing device such as an electromechanical arc gap and a point contact relay. These devices would typically be used in series with a test load to generate actual series arcing to test the AFCI device for its ability to detect series arcing. However, such a prior art device has many disadvantages. For example, the electromechanical arc gap and relay are large mechanical devices that consume much space. Another disadvantage is that closing and opening the point contact relay results in series arcing which may interfere with the intended signal induced by the electromechanical arc gap. Also, it is difficult to build an electromechanical arc gap with consistent signal characteristics which are necessary for testing AFCI devices with repeatable results, especially in large volumes. Furthermore, it is difficult to control or calibrate characteristics of the arc signal generated from the aforementioned prior art series arcing device. Such control and calibration are necessary in order to achieve testing of AFCI devices with repeatable results. Another disadvantage is that series arcing is destructive to the electrodes across an arc gap and require constant replacement. Yet another disadvantage is that the characteristics of the arc signal are affected by the destruction of the electrodes across an arc gap, the heating of the electrodes across an arc gap, the heating of the environment in and around the arc gap, and the relative humidity of the environment in and around the arc gap. Finally, there is the potential for electric shock if the arc gap is exposed.
Thus, there exists a need for a method and an apparatus for testing AFCI devices for series arc detection that substantially eliminate the foregoing problems.